Method and apparatus for scrubbing the bond pads of an integrated circuit during wafer sort

ABSTRACT

A method and apparatus for electrically coupling the bond pads of an integrated circuit to a tester using a probe card having a biasing element supporting a plurality of tests probes. In one embodiment, the method includes the steps of placing the test probes in contact with the bond pads and providing a vibrational movement to the biasing element such that the test probes move relative to the bond pads and such that the test probes remove an electrically non-conductive material on the surface of the bond pads to establish an electrical connection between the test probes and the bond pads.

This is a divisional of application application Ser. No: 08/590,542,filed Jan. 24, 1996, now abandoned.

FIELD OF THE INVENTION

The present invention relates to the field of semiconductor testingequipment and, more specifically, to the field of probe cards andprobers for semiconductor test systems.

BACKGROUND OF THE INVENTION

In the manufacture of semiconductor devices it is advisable that suchcomponents be tested at the wafer level to evaluate their functionality.The process in which die on a wafer are tested is commonly referred toas "wafer sort." Testing and determining design flaws at the die leveloffers several advantages. First, it allows designers to evaluate thefunctionality of new devices during development. Increasing packagingcosts also make wafer sorting a viable cost saver, in that thereliability of each die on a wafer may be tested before incurring thehigh costs of packaging.

Wafer sorting typically involves the use of probing technology wherein aprobe card containing probe features engages the bond pads on a die soas to connect the pads to a tester. FIGS. 1A, 1B and 1C illustrates atypical testing apparatus including a tester 10, test head 11, andhandler 12, that is used to test the performance of a die on a wafer. Asillustrated, probe card 14 sits below and in contact with test head 1 1.During testing, the handler supports the wafer on platform (chuck) 16and positions the wafer so as to precisely align the bond pads of a dieto be tested with the probe features on the probe card. Chuck 16 isconnected to a staging device 18 by rods 17. The staging device 18typically positions the chuck along an x-y plane by moving along a stagefloor 13 on a ball screw stage assembly. Staging device 18 may alsoposition the chuck by floating above the stage floor on a magnetic airbearing. Chuck 16 typically comprises a vacuum chuck wherein the waferbeing tested is held in position by drawing a vacuum within a pluralityof interconnecting channels 19 that are formed within the surface of thechuck. Once aligned, chuck 16 is raised via rods 17 such that the bondpads of the die are forced against the probe features on the probe card.

All categories of probing utilize some form of "scrub" at the touch downphase of a probe feature to a bond pad. Scrub applies to probed aluminumor lead, where the probe features on a probe card pierce (scrub) thelayer of oxide, a nonconductive film that grows quickly on exposedaluminum and lead. Generally, scrub applies to any nonconductive layerthat produces a barrier between the test probes of a probe card and thebase metal of a bond pad. The purpose of the scrub is to break throughthe non-conductive layer on the bond pads in order to establish a goodelectrical contact between the probe features and the base metal of thebond pads. Scrub occurs when the handler forces the wafer, and,subsequently, the bond pads of a die, against the probe features on theprobe card causing the probe features to deflect. The scrub is generatedby a small horizontal movement of each probe feature across the surfaceof each corresponding bond pad as the probe features deflect. As theprobe features move across the bond pads they penetrate thenonconductive oxide layer thereby establishing a good electrical contactbetween the probe features and the bond pads. This type of scrub isreferred to as "passive" scrub. Typically, the amount of deflection ofthe probe features, and, hence, the amount of scrub achieved, isproportional to the force applied by the movement of the wafer againstthe probe card features. The additional movement of a wafer toward aprobe card after initial contact with a probe feature is known as"overdrive."

Probe cards presently available are of the passive scrub type. Thecantilever tungsten needle probe card 20, as illustrated in FIG. 2, isone example. As shown in FIG. 2, probe card 20 possesses a fiberglassepoxy-base printed circuit board 21 with tungsten needles 22 extendingout from the probe card and held in position by an epoxy ring 28. Eachneedle contains a tip (probe feature) 23 for making contact with thebond pads of a die. As previously discussed, the amount of scrubachieved on the surface of a bond pad is proportional to the forceapplied by the movement of the wafer against the probe card features. Atungsten needle probe card, as illustrated in FIG. 2, typically requiresoverdrive levels of 0.002 to 0.004 inches to achieve good electricalcontact at the bond pads.

There are a number of problems associated with the passive scrubcantilever needle probe card. First, the high overdrive levels requiredto achieve good electrical contact between the probe features and diebond pads cause the probe features to bend, break and wear more quickly,resulting in increased replacement and repair costs. High overdrive alsoincreases the probability that deep and damaging scrub marks will resultmaking it difficult to bond wires to the die pad. Another problemassociated with passive scrub cantilever needle probe card is that itsometimes requires two or more touchdowns per die test to break throughthe pad oxidation layer. This creates two problems. First, it prolongsthe amount of time required to perform a die test. Secondly, itdiminishes the effective life of a probe card.

Yet another problem with passive scrub needle cards is that strayparticle and oxide buildup often occur at the tip of the probe features.Stray particle and oxide buildup contributes to high contact resistancebetween the probe feature and bond pad. High contact resistance causesinaccurate voltage levels during device testing due to the voltageproduced across the probe tip. This may cause a device to incorrectlyfail test resulting in lower test yields.

Membrane probe cards were developed to address some of the problemsassociated with tungsten needle probe cards. Namely, membrane probecards were developed to provide a smaller and more uniform scrub alongthe bond pad surface. FIGS. 3A and 3B illustrate a cross-sectional viewof a typical membrane probe card. As shown, probe card 30 possesses aflexible printed circuit (membrane) 31 having spherical contact bumps(probe features) 32. The contact bumps are generally coupled to anepoxy-base printed circuit board 34 that provides structural support formembrane 31 and electrically connects probe card 30 to the test head ofa wafer sort tester. Photolithography is used to manufacture contactbumps 32, hence, the probe feature geometries that are achieved aresmall and precise. Column spring 33 provides both support and resilienceto the membrane structure. The spring constant of column spring 33establishes the amount of force that is required to deflect membrane 31in order to achieve scrub at the contact bump and die pad interface.

Although smaller and more precise scrub geometries are achievable usingmembrane type probe cards, there exists two major draw backs associatedwith their use. First, the amount of scrub that is actually obtained istypically minimal or non-existent. That is, the probe features are oftenunable to pierce the oxidation layer of the die pad unless the die padis very clean. Secondly, membrane probe features 32 are prone toclogging and must be cleaned on a relatively frequent basis. Because itis difficult to clean the membrane features without damaging them, theuseful life of a membrane probe card is typically much shorter than thatof a cantilever needle probe card. For these reasons, the use ofmembrane probe cards are generally avoided in full-scale manufacturingapplications.

Thus, what is needed is a method and apparatus for electrically testingthe functionality of wafers that solves the problems associated withcurrent passive scrub techniques.

SUMMARY OF THE INVENTION

The present invention is an improved apparatus and method forestablishing an electrical connection between the bond pads of anintegrated circuit and the test probes of a probe card. In oneembodiment an actuator assembly is attached to a standard cantileverneedle probe card. The actuator assembly includes a base that isattached to the center of the probe card printed circuit board. Disposedwithin the base are two piezoelectric actuators disposed along oppositesides of the base. The actuators are secured in position by a spring,retainer and fastening device. A weight is disposed atop each actuatorto control the frequency and amplitude of movement generated by thedevices. In accordance with the present invention, an electricalconnection is established between the test probes of the probe card andthe bond pads of the integrated circuit by first placing the bond padsin intimate contact with the test probes. In order to penetrate theoxidation layer that exists along the surface of the bond pads, thepiezoelectric actuators are then used to create a controlled movementbetween the test probes and the bond pads. Hence, the present inventionutilizes an "active" scrub method for establishing a electricalconnection between the test probes of a probe card and the bond pads ofan integrated circuit.

In another embodiment, an actuator assembly is attached to a membraneprobe card. The actuator assembly includes a base, a spring, apiezoelectric actuator and an actuation link that connects the assemblyto the probe card column spring. Scrub is achieved by placing themembrane probe bumps in contact with their respective bond pads alongthe surface of an integrated circuit and activating the piezoelectricactuator to provide a side ways movement of the probe bumps relative tothe bond pads.

In another embodiment of the present invention, an actuator assembly isattached to the chuck of a handler to provide a relative motion betweenthe bond pads of an integrated circuit and the probe features of a probecard during scrub. In one particular embodiment, the actuator assemblyis attached to the chuck by a collar and clamping apparatus.

In yet another embodiment of the present invention, the handler isequipped with a base that is coupled to a chuck via a mounting dish andplurality of pivot leaf springs. An actuator assembly is attachedbetween the mounting dish and base to provide a relative movementbetween the chuck and base. Scrub is achieved by engaging the probefeatures of a probe card against the bond pads of an integrated circuitbeing held within the chuck and activating the piezoelectric actuator.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example and is notlimited by the figures of the accompanying drawings, in which likereferences indicate similar elements, and in which:

FIG. 1A illustrates a typical prior art tester, test head and handler.

FIG. 1B illustrates a side view of the handler depicted in FIG. 1A.

FIG. 1C illustrates a top view of the vacuum chuck depicted in FIG. 1B.

FIG. 2 illustrates a typical prior art cantilever needle probe card.

FIG. 3A illustrates a typical prior art membrane probe card.

FIG. 3B illustrates a enlarged view of the membrane, probe features andspring of the probe card depicted in FIG. 3A.

FIG. 4A illustrates a one embodiment of the present invention having anactuator assembly attached to a cantilever needle probe card.

FIG. 4B illustrates a top view of the actuator assembly depicted in FIG.4B.

FIG. 5A illustrates a another embodiment of the present invention havingan actuator assembly attached to a membrane probe card.

FIG. 5B illustrates an enlarged view of the actuator assembly shown inFIG. 5A.

FIG. 6A illustrates yet another embodiment of the present inventionhaving an actuator assembly attached to the vacuum chuck of a handler.

FIG. 6B illustrates a top view of the chuck assembly depicted in FIG.6A.

FIG. 7A illustrates one embodiment of the actuator mounting collardepicted in FIGS. 6A and 6B.

FIG. 7B illustrates a cross-sectional side view of the actuator assemblydepicted in FIG. 7A.

FIG. 8A illustrates another embodiment of the present invention.

FIG. 8B illustrates a top view of the chuck, base and actuator assemblydepicted in FIG. 8A.

FIG. 8C depicts a side view of the chuck, actuator assembly and base inthe embodiment illustrated in FIG. 8A.

DETAILED DESCRIPTION

An apparatus and method that provides an improved electrical connectionbetween the test probes of a probe card and the bond pads of anintegrated circuit is described. In the following description, numerousspecific details are set forth such as material types, dimensions,processing steps, etc., in order to provide a thorough understanding ofthe present invention. However, it will be obvious to one of skill inthe art that the invention may be practiced without these specificdetails. In other instances, well known elements and processingtechniques have not been shown in particular detail in order to avoidunnecessarily obscuring the present invention.

FIG. 4A illustrates an active scrub probe card 40 of one embodiment ofthe present invention. As shown, probe card 40 includes a standardcantilever needle probe array 49 that is attached to a printed circuitboard (PCB) 41. Attached to PCB 41 is an actuator assembly comprising abase 42, piezoelectric actuators 43, weights 44, springs 45, retainers46 and fasteners 47. The actuator assembly is attached to PCB 41 bythreaded fasteners 48. A salient feature of the present invention liesin the manner in which scrub achieved.

As previously discussed, there are a number of problems associated withthe use of passive scrub is devices. The present invention addressesthese problems by providing an actuator assembly that is capable ofcreating a small, precise, variable and electrically-actuated movementbetween the test probes of a probe card and the bond pads of anintegrated circuit. In accordance with the present invention, a reliableelectrical contact is established between the test probes of a probecard and the bond pads of an integrated circuit by first placing thetest probes and bond pads in intimate contact. Once the test probes andbond pads make contact, a controlled cyclic movement is applied to thetest probes such that the test probes penetrate the oxidation layer onthe bond pad surface.

Referring again to FIG. 4A, an actuator assembly is shown whereinpiezoelectric actuators 43 and springs 45 are provided to produce anoscillating or cyclic movement to the cantilever needle probe array 49when a voltage is applied to actuators 43. The frequency and amplitudeof the cyclic movement produced by the piezoelectric actuators 43 iscontrolled, in part, by weights 44 that are attached atop thepiezoelectric actuators. In the embodiment of FIG. 4A, the actuatorassembly produces an upward and downward movement of test probes 49causing the test probes to deflect against the bond pads of theintegrated circuit (not shown) in a repetitive and rapid fashion. Thedepth, length and continuity of the scrub mark produced along the bondpad surface is determined by the frequency, amplitude and duration ofthe movement induced by the actuator assembly in conjunction with thescrub geometry and the amount of overdrive. It is appreciated that anumber of variables determine the frequency and amplitude of the inducedmovement. These include: the size and type of piezoelectric actuators43, the mass of weights 44, the flexibility of PCB 41, the voltageapplied to piezoelectric actuators 43, the spring constant of springs45, etc.. By precisely controlling the frequency, amplitude, time ofscrub and the duration of the movement induced by the actuator assembly,a number of advantages may be realized using the active scrub method ofthe present invention. For example, lower overdrive levels may be usedresulting in a longer probe card life. The active scrub method alsoprovides an inherent cleaning method that limits the stray particle andoxide buildup that often occurs at the test probe tip. By periodicallyactivating the piezoelectric devices between scrubbing events, a testprobe "cleaning" mode may be established that effectively minimizes thestray particle and oxide buildup at the test probe tip. A specialcleaning surface may also be used to implement a special test probe"cleaning" mode. The present invention also offers the opportunity todevelop specialized software "recipes" (specific combinations ofvariable settings) for different integrated circuit designs andmanufacturing processes. In this manner, the present invention mayaccommodate bond pad and oxidation layer variations while optimizing thewafer sort process.

As illustrated in FIG. 4A, actuators 43 are disposed within a base 42that is attached to a standard cantilever needle probe card. Actuators43 may comprise any of a variety of piezoelectric actuators, such as,for example, the NEC brand multilayer, AE series, piezoelectricactuators. Actuators 43 are typically attached to base 42 by an epoxyresin adhesive. It is appreciated, however, that any of a number ofother attachment methods may be used. For example, a clamping device maybe used in lieu of an adhesive. Base 42 comprises a material thatpossesses a coefficient of thermal expansion that is substantiallysimilar to expansion coefficient of actuators 43. In one embodiment,base 42 comprises Invar, a high temperature nickel alloy. Similarly,weights 44 typically comprises a material having a coefficient ofthermal expansion that is substantially similar to that of actuators 43.The mass of weights 44 may vary depending upon the particular scrubrequirements. The weights are secured to actuators 43 by an adhesive. Itis understood, however, that a variety of other attachment methods mayalso be used. Springs 45 provide a given resistance to the upward anddownward movement of actuators 43. Springs 45 act in combination withweights 44 to control the frequency and amplitude of the movementproduced by actuators 43. Retainers 46 and fasteners 47 comprisestainless steel and are provided to secure the springs to the actuatorassembly.

FIG. 4B illustrates a top view of the embodiment depicted in FIG. 4A. Asshown, actuators 43 comprise electrical wires 51 for connecting theactuators to a voltage source. Power may be supplied to actuators 43 bya constant or variable voltage source. Also note, that through holes 50are provided within base 42 to accommodate fasteners 48 that are used toattach the actuator assembly to PCB 41.

In one embodiment, the present invention is implemented by bringing thebond pads of an integrated circuit in contact with the test probes 49 ofprobe card 40. Once the bond pads (not shown) and test probes are inintimate contact, a controlled cyclic movement of the test probes isproduced by providing a voltage to actuators 43. The actuation frequencyof test probes 49 is generally held between 100 to 1000 Hertz. Theduration of the scrub is typically between 0.3 to 1.0 seconds.

Although an actuator assembly comprising two piezoelectric actuators hasbeen described in the embodiment of FIG. 4A, it is appreciated that anyof a number of types of actuators may be used in the implementation ofthe present invention. In addition, it is understood that theimplementation of the present invention is not limited to the use ofpiezoelectric actuators. Other actuation means, such as ultra sound andvoice coils, may be used to implement the invention. Moreover, it isappreciated that the actuator assembly described in the embodiment ofFIG. 4A is not limited to a cantilever needle probe card but may also beused in conjunction with a membrane probe card.

FIG. 5A illustrates an active scrub probe card 60 of another embodimentof the present invention. As shown, probe card 60 includes a membranestyle probe card having probe bumps 62 disposed along the bottom surfaceof membrane 63 that is supported by a column spring 64. Attached to PCB61 is an actuator assembly 70. As illustrated in FIG. 5B, actuatorassembly 70 includes a base 65, a spring 74, a piezoelectric actuator 71and an actuation link 72 that connects the assembly to the probe cardcolumn spring 64. An actuator bridge plate 73 and a support screw 75 isused to secure actuator 71 and spring 74 to actuation link 72. Spring 74is attached to base 65 with threaded fastener 76. The actuator assemblybase 65 is attached to PCB 61 via flat head threaded fasteners 66.Although a single actuator assembly has been described, it is should benoted that two or more actuator assemblies may be used in theimplementation of the invention.

As previously discussed, current passive scrub type membrane probe cardsare generally avoided in full-scale manufacturing applications becauseof their inability to penetrate the bond pad oxidation layer in arepeatable and reliable fashion. The probe bumps (test probes) of amembrane card are also prone to clogging. The present inventionaddresses these problems by providing an actuator assembly 70 thatenables the membrane test bumps 62 to penetrate the oxidation layer on abond pad in a reliable and repeatable manner. In accordance with thepresent invention, scrub is achieved by placing the membrane probe bumps62 in contact with their respective bond pads along the surface of anintegrated circuit and activating the piezoelectric actuator 71 toprovide a controlled side ways movement of probe bumps 62 relative tothe bond pads. The depth, length and continuity of the scrub markproduced along the bond pad surface is largely determined by thefollowing factors: 1) the size and type of actuator 71; 2) the springconstant of springs 64 and 74; 3) the mass and geometric configurationof the actuator assembly support structure; and 4) the flexibility ofmembrane 62 and PCB 61. As an example, the actuation angle of actuationlink 72 will affect the horizontal movement of membrane test probes 62.To address the problems associated with the clogging of probe bumps 62,a special cleaning mode may be implemented in a manner similar to thatdisclosed above in the description of the embodiment of FIG. 4A.

In one embodiment of the present invention, actuator 71 comprises a NECbrand, AE series, multilayer piezoelectric actuator. Actuator 71 issecured to actuation link 72 via a t-shape actuation bridge 73 thatcomprises Invar, a high temperature nickel alloy. Actuation link 72typically comprises stainless steel whereas base 65 comprises a materialthat has a coefficient of thermal expansion that is substantiallysimilar to that of PCB 61. In one embodiment, base 65 comprises Invar.

In the foregoing discussion, a cleaning mode has been described wherethe test probes of a probe card are cleaned by periodically activatingthe piezoelectric devices between scrubbing events. A special cleaningsurface having a textured surface has also been described as a means toimplement the cleaning mode. In one embodiment of the present inventiona vibrating cleaning surface may be provided as an attachment to thehandler or as a stand-alone unit. In this manner, the test probes of aprobe card may be cleaned by bringing the test probes into contact withthe cleaning surface and vibrating the cleaning surface in relation tothe probe features. In one embodiment, the vibrating or oscillatingmovement of the cleaning surface is provided by a piezoelectricactuator.

FIG. 6A illustrates yet another embodiment of the present inventionwherein an actuator assembly 90 is attached to the chuck 81 of a handlerassembly 80 to provide a relative motion between the bond pads of anintegrated circuit and the test probes of a probe card during scrub.Note that in the embodiment of FIGS. 4A and 5A scrub is achieved byproviding movement to the test probes relative to the bond pads on anintegrated circuit. In the embodiment of FIG. 6A, scrub is achieved byproviding a movement to the integrated circuit instead of the probe cardfeatures.

As shown, FIG. 6A illustrates a typical handler assembly 80. Assembly 80includes a chuck 81 and a positioning stage 82 that rides along a stagefloor 83 for positioning the chuck along an x-y direction. Rods 84connect chuck 81 to the positioning stage and are used to raise thechuck, and consequently, the integrated circuit that rests on the chuck,up against the test probes of a probe card during a typical wafer sortprocess.

FIG. 6B illustrates a top view of the chuck and actuator assemblydepicted in FIG. 6A. Chuck 81 typically comprises a vacuum chuck whereinthe integrated circuit device being tested is held in position bydrawing a vacuum within a plurality of interconnecting channels 86formed within the surface of the chuck. Actuator assembly 90 is attachedto chuck 81 by an actuator mounting collar 85 (See FIG. 7B). FIG. 7Aillustrates a top view of the mounting collar assembly 85. Integrallyformed within collar 85 is a mounting base 98 that supports the actuatorassembly. Mounting collar 85 includes a clamp 87 for securing the collarto chuck 81.

Turning to FIG. 7B, a side view of actuator assembly 90 is shown. Theassembly includes a piezoelectric actuator 92 that is secured between abase 91 and a weight 93. Spring 94 acts against weight 93 to provide agiven resistance along one surface of the weight. Weight 93 and spring94 act, in part, to control the frequency and amplitude of the movementproduced by actuator 92. Actuator 92 is generally attached to base 91and weight 93 by an adhesive 97, such as an epoxy resin. Weight 93 andbase 91 comprise a material that has a coefficient of thermal expansionthat is substantially similar to that of actuator 92. Actuator 92possesses electrical wires 96 for coupling the actuator to a powersource. The assembly base 91 is attached to actuator mounting collar 85at the collar base 98. A threaded fastener 95 is used to connect themounting collar base 98 to actuator base 91.

FIG. 8A illustrates another embodiment of the present invention whereinthe handler assembly 100 is equipped with a base 104 that is coupled toa chuck 101 via a plurality of pivot leaf springs 105 and an actuatorassembly 106. Actuator assembly 106 is attached between a mounting dishand base to provide a relative movement between the chuck and base.Scrub is achieved by engaging the test probes of a probe card againstthe bond pads of an integrated circuit being held within chuck 101 andactivating the piezoelectric actuator within assembly 106. In thismanner, the bond pads of the integrated circuit are moved relative tothe probe card test probes producing a controlled scrub of the oxidationlayer on the surface of the bond pads.

FIG. 8B illustrates a top view of the chuck, base and actuator assemblyof FIG. 8A. Chuck 101 typically comprises a vacuum chuck and includes aplurality of channels 112 disposed along its surface. As shown in FIGS.8A and 8B, actuator assembly 106 is attached to chuck 101 and base 104.Note also, that a plurality of pivot leaf springs 105 mechanicallycouple chuck 101 to base 104. It is noted that a number of other biasingmeans may be used in lieu of springs 105. As illustrated, in oneembodiment actuator assembly 106 is attached to chuck 101 via a mountingcollar 107 similar to that described in the embodiment of FIG. 7A. Notehowever, that a mounting collar is not necessary to implement thepresent invention. It is appreciated that actuator assembly 106 may beattached to the base or chuck by any of a number of attachment methodscommonly known in the art.

FIG. 8C illustrates a side view of the chuck 101, base 104 and actuatorassembly 106 of the present invention. As shown a piezoelectric actuator120 is positioned between an actuator base 114 and chuck 101. Thefrequency of the movement created between chuck 101 and base 104 iscontrolled, in part, by pivot leaf springs 105. For example, thefrequency of the movement between the two parts may be varied byincreasing or decreasing the number of springs, changing the position ofthe springs or varying the flexibility (spring constant) of the springs.The amplitude of the induced oscillation is largely controlled by theactuator displacement and the geometry of the actuating structure. Othervariables, such as the mass of base 114 and chuck 101, may also beadjusted to control the movement of chuck 101 relative to base 104 whenactuator 120 is activated. In lieu of directly attaching pivot leafsprings 105 to chuck 101, the base 104 may be attached to a mountingdish or other platform structure that holds chuck 101.

In the foregoing discussion, cantilever needle probe cards and membraneprobe cards have been described in the implementation of the presentinvention. It is to be understood, however, that the present inventionis applicable to any of a number of other probe cards, includingvertical and spring based probe cards. Moreover, practitioners in theart will appreciate that the scope of the present is not limited toprobe cards but may used in conjunction with any structure containingtest probes. It is further understood that the present invention is notlimited to the scrubbing of oxidation layers on integrated circuit bondpads. The invention may be used in any application wherein the removalof an electrical insulator layer, or other non-conductive particles, isrequired to establish a good electrical connection between the probefeatures of a tester and the base metal of a bond pad.

Thus, an apparatus and method for providing an improved electricalconnection between the test probes of a probe card and the bond pads ofan integrated circuit is described. Although many alternations andmodifications to the present invention will no doubt become apparent tothe person of ordinary skill in the art after having read the foregoingdescription, it is to be understood that the particular embodimentsshown and described by way of illustration are in no way intended to belimiting. It is further understood that the relative dimensions,geometric shapes, materials and process parameters set forth within thespecification are exemplary of the disclosed embodiments only. Otherembodiments may utilize different dimensions, shapes, materials, andprocess steps, etc., to achieve substantially the same results.

What is claimed is:
 1. An improved method for electrically coupling thebond pads of an integrated circuit to a tester using a probe card havinga plurality of test probes, said method comprising the steps of:a)placing said integrated circuit on a holder of an assembly, wherein theassembly also includes a base connected to said holder by apiezoelectric actuator, and a positioning stage providing support forsaid base; b) placing said test probes in contact with said bond pads ofsaid integrated circuit; and c) enabling the piezoelectric actuator toprovide a horizontal movement to said holder such that said holder movessaid integrated circuit relative to said test probes, wherein inresponse to said horizontal movement said test probes pierce anelectrical insulation layer on said bond pads to establish an electricalconnection between said test probes and said bond pads.
 2. An improvedhandler for positioning the bond pads of an integrated circuit inintimate contact with the test probes of a probe card, said handlercomprising:a platform having a top for holding said integrated circuit;means for positioning said platform such that said test probes of saidprobe card make intimate contact with said bond pads; an actuatorcoupled to said platform such that when the actuator is activated saidintegrated circuit moves horizontally relative to said test probes suchthat said test probes pierce an electrically non-conductive layer onsaid bond pads when said test probes and said bond pads make intimatecontact.
 3. The handler of claim 2 wherein said platform includes avacuum chuck.
 4. The handler of claim 2 wherein said actuator assemblyincludes a piezoelectric actuator.
 5. A handler assembly for positioningbond pads of an integrated circuit in intimate contact with test probesof a probe card, said handler comprising:a platform for holding saidintegrated circuit; an actuator assembly connected to said platform; abase connected to said actuator assembly; a positioning stage coupled tosaid base, said positioning stage for positioning the platform in an X-Yplane such that when said platform is raised the bond pads make intimatecontact with the test probes, wherein the actuator assembly is activatedwhen the bond pads make intimate contact with the test probes such thatthe platform vibrates the integrated circuit relative to the base andindependent of the positioning stage, and wherein the actuator assemblyvibrates the platform in the X-Y plane.
 6. The handler assembly of claim5 further comprising a biasing element interposed between said platformand said base and cooperating with the actuator assembly to control thevibration of the platform relative to the base.
 7. The handler assemblyof claim 6 wherein the biasing element is a pivot leaf spring.
 8. Thehandler assembly of claim 7 wherein the actuator assembly comprises apiezoelectric actuator.
 9. The handler assembly of claim 7 furthercomprising a mounting dish interposed between the base and the platform.10. The handler assembly of claim 5 further comprising a plurality ofrods for coupling said positioning stage to said platform and forraising said platform.